In this fast-track application, we propose to develop a Computer Adaptive Test (CAT) to provide universal ongoing, continuous progress assessment data of critical reading skills to teachers of students in grades 4 to 8. The primary purpose of this assessment will be to facilitate a teacher's ability to provide differentiated instruction for all students in these grades, including student who struggle as well as student who excel. We will call this assessment Continuous Monitoring of Advanced Reading Skills (CMARS, pronounced SEE-mars). During Phase I we propose to develop and program a large pool of items spanning the reading abilities of students in grades 4 to 8 that will allow us to measure growth in critical areas of reading. The size of the item pool must be sufficiently large to allow students to be assessed monthly. To achieve the aims of Phase I, we will (a) develop a large item pool across each of 4 domains of reading including: Word Analysis, Fluency, Vocabulary, and Comprehension; (b) field test item delivery formats with middle grade students to ensure that students in this age group understand and can complete each task independently, as well ensure they find the tasks age appropriate, motivating, and engaging; and (c) program all CMARS items incorporating high quality graphics and animation and an engaging game like theme. During Phase II we propose to complete CMARS as a CAT-driven CPM reading assessment tool with proven technical adequacy. To achieve this Phase II aims, we will: (a) conduct Item Response Theory (IRT) research on our pool of items by administering the entire pool of items via computer administration to a large number of middle grade students in order to determine item parameters, as well as and determine which items do not perform as intended and need to be culled from the item pool; (b) use the data collected from our IRT work, to program the items to an existing Computer Adaptive Testing (CAT); and (c) conduct an evaluation of the reliability, concurrent, and predicative validity of CMARS to other well established measures of reading. At the completion of this Fast Track project, we will have (a) completed programming of all CMARS items subtests and, (b) assessed the psychometric qualities of our computer- administered measures by comparing them to already establish examiner-administered measures, (c) completed programming for data display and reporting information back to teachers and schools.